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A. Fib

Atrial Fibrillation (AF) is the most prevalent cardiac dysrhythmia in the United States and a substantial cause of morbidity and mortality.1 Even though AF is commonly diagnosed by clinicians; the most appropriate treatment course remains elusive. The main controversy is between controlling the rate versus the rhythm. The ventricular rate is the number of cardiac cycles (systole and diastole) in one minute, normally 60 to 100 beats per minute (bpm) in an adult; it can be determined on an electrocardiogram (ecg) by measuring the distance between R waves.2 The rate is typically pharmacologically controlled by beta or calcium channel blockers. A normal sinus rhythm demonstrates an electrical impulse generated by the sinoatrial node or "pacemaker" of the heart and maintains a consistent R-R interval on the ecg.2 AF is associated with an "irregularly irregular" rhythm due to the erratic atrial depolarization and the resulting variable ventricular response.2 AF is expressed on an ecg as a wavy baseline with an atrial rate of 400 to 600 bpm "without identifiable P waves."2 The rhythm found in AF is controlled with electrocardioversion or antiarrhythmic drugs, such as flecainide, quinidine, and amiodarone.1
Over the last decade there have been advancements in the understanding of the pathophysiology of AF which has aided further exploration of the appropriate treatment through several key studies. For example, the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study concluded that there was no significant difference between the two treatment strategies.3 However, the rhythm control group was associated with slightly more adverse drug effects and hospitalizations than the rate control group studied.3 Other related key studies include the Pharmacological Intervention in AF (PIAF), Rate Control versus Electrical Cardioversion for Persistent AF (RACE), Canadian Registry of AF cohort (CARAF), How to Treat Chronic AF (HOT CAFE) and...